Tabby's star [wikipedia.org], aka KIC 8462852, is likely surrounded by orbiting dust grains that block ultraviolet light [scientificamerican.com]:
The bizarre long-term dimming of Tabby's star [space.com]—also known as Boyajian's star, or, more formally, KIC 8462852—is likely caused by dust, not a giant network of solar panels or any other "megastructure" built by advanced aliens, a new study suggests.
Astronomers came to this conclusion after noticing that this dimming was more pronounced in ultraviolet (UV) than infrared light. Any object bigger than a dust grain would cause uniform dimming across all wavelengths, study team members said.
"This pretty much rules out the alien megastructure theory, as that could not explain the wavelength-dependent dimming," lead author Huan Meng of the University of Arizona said in a statement [nasa.gov]. "We suspect, instead, there is a cloud of dust orbiting the star with a roughly 700-day orbital period."
Aliens left to roam free once again.
Previously: Tabby's Star Under Observation After Dimming Event Detected [soylentnews.org]
Tabby's Star Dimming Could be Explained by a Saturn-Like Exoplanet [soylentnews.org]
Extinction and the Dimming of KIC 8462852 [iop.org] (DOI: 10.3847/1538-4357/aa899c) (DX [doi.org]) (arXiv [arxiv.org])